Anonymous posting is only appropriate when you are revealing sensitive employment related information about a firm, job, etc. You may anonymously respond on topic to these threads. Unacceptable uses include: harassing another user, joking around, testing the feature, or other things that are more appropriate in the lounge.

Nope, a CB is a CB. A screener is more about looking through the resume, assessing grades, work experience, etc. with your personality and conversational skills obviously playing a part, but the resume screening is most important. Once you are at the CB stage, they have screened you and you passed the first test. So go in there and treat it just like any other CB, since they will be doing the same.